HR: 1340h
AN: B43A-0139    [Abstracts]
TI: Estimating Scalar Fluxes in Tropical Forests from Concentration/Temperature Profile Measurements
AU: * Silva, R
EM: renato@duke.edu
AF: Department of Civil and Environmental Engineering, Pratt School of Engineering, Duke University, Box 90287 Hudson Hall Duke University, Durham, NC 27708-0287 United States
AU: Siqueira, M
EM: mbs4@duke.edu
AF: Nicholas School of the Environment and Earth Sciences, Duke University, Box 90328 Duke University Levine Science Research Center, Durham, NC 27708 United States
AU: Katul, G
EM: gaby@duke.edu
AF: Nicholas School of the Environment and Earth Sciences, Duke University, Box 90328 Duke University Levine Science Research Center, Durham, NC 27708 United States
AU: Rocha, H
EM: humberto@model.iag.usp.br
AF: Instituto de Astronomia Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Rua do Matao, 1226 Cidade Universitaria, Sao Paulo, SP 05508-900 Brazil
AU: Goulden, M
EM: mgoulden@uci.edu
AF: Department of Earth System Science, University of California Irvine, Croul Hall, Irvine, CA 92697-3100 United States
AU: Miller, S
EM: sdmiller@uci.edu
AF: Department of Earth System Science, University of California Irvine, Croul Hall, Irvine, CA 92697-3100 United States
AB: Eddy Covariance (EC) flux measurements are now widely used for estimating long-term biosphere-atmosphere gas exchange. However, gap-filling and constraining these EC estimates using other techniques that are sensitive to different assumptions remains a high priority. Improved ability to recover fluxes from concentration and temperature profile data could serve as one such constraining and gap-filling method. Furthermore, if successful, concentration profiles permit estimating fluxes of chemical fluxes for which high frequency gas analyzers are not currently available. We investigate the ability of higher order closure models to estimate CO2 fluxes from a 40 m tall tropical forest on the Floresta Nacional do Tapaj¢s, Para, Brazil. Eddy covariance measurements of sensible and latent heat, CO2 and momentum fluxes were collected along with profile measurements of CO2 and water vapor concentrations and temperature as part of the LBA program. To this end, we extended a 2nd order Eulerian approach for CO2 along with the appropriate stability correction regimes. Also, we included in the model transient term in an attempt to improve estimates over periods in which storage and turbulent fluxes may be of comparable magnitude. For comparison, we performed calculations using a 1st order closure model and a "dummy" model where perfect similarity between heat and CO2 transfer is assumed.
DE: 1610 Atmosphere (0315, 0325)
DE: 1615 Biogeochemical processes (4805)
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting